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J. Reitterer, F. Fidler, G. Schmid, C. Hambeck, F.S. Julien-Wallsee, W. Leeb, U. Schmid:
"Beam-clipping-induced diffraction effects in MEMS laser scanners for autostereoscopic outdoor displays";
Sensors and Actuators A: Physical, 233 (2015), 582 - 589.

In micro-electro-mechanical systems (MEMS) laser scanners, the beams reflected by the micromachined
mirror may be truncated at various edges in the system, e.g., due to finite size of the reflective mirror
surface, at the rigid supporting mirror frame, and at the package of the light source. In this paper the joint
effect of such individual beam clipping is described by introducing a so-called effective system aperture.
Diffraction effects induced by this virtual aperture are analyzed by means of Fourier optics incorporating
the Fraunhofer far field approximation. The beam clipping theory is then applied to a laser light module
with integrated MEMS mirror for autostereoscopic outdoor displays. Employing an optimization of the
MEMS mirror tilting angle with respect to the laser light source, the beam-clipping-induced diffraction
effects are minimized.

In micro-electro-mechanical systems (MEMS) laser scanners, the beams reflected by the micromachined
mirror may be truncated at various edges in the system, e.g., due to finite size of the reflective mirror
surface, at the rigid supporting mirror frame, and at the package of the light source. In this paper the joint
effect of such individual beam clipping is described by introducing a so-called effective system aperture.
Diffraction effects induced by this virtual aperture are analyzed by means of Fourier optics incorporating
the Fraunhofer far field approximation. The beam clipping theory is then applied to a laser light module
with integrated MEMS mirror for autostereoscopic outdoor displays. Employing an optimization of the
MEMS mirror tilting angle with respect to the laser light source, the beam-clipping-induced diffraction
effects are minimized.

Laser scanner; MEMS mirror; Beam clipping; Beam divergence; Autostereoscopic laser display

http://dx.doi.org/10.1016/j.sna.2015.06.024